The present invention relates to a plastic fender of a motor vehicle, having a plurality of spaced-apart elongated holes extending longitudinally in thermal expansion directions of the fender along a first edge area on a hood side and along a second edge area on a support column side which extends at an angle thereto for admitting a holding element which in turn is fixed to a vehicle body, and as disclosed in European publication EP 0 523 052 B1, on page 2, lines 9 to 28.
Since a plastic fender elongates under the action of high heat, the plastic fender described on page 2 of this European publication is rigidly fixed at its edge area on the support column side, while its edge area on the hood side has a plurality of spaced-apart elongated holes for admitting mounting screws. In case of thermal expansion, the plastic fender can shift along the elongated holes on the hood side while its edge area on the support column side is rigidly fixed. This has a drawback in that, during painting of the vehicle, the process temperatures of approximately 200° C. can cause a plastic fender mounted to the body to bulge along its rigid edge area and to deform permanently under some circumstances.
An object of the invention is thus to mount a plastic fender to a vehicle body such that bulging of the fender during thermal expansion is prevented along all the edge areas.
This object is attained by having the fender fixedly mounted to the vehicle body in a corner region between a first edge area and a second edge area, and by having the mounting sections of guide elements, which in turn are fixedly mounted to the vehicle body, engage in the elongated holes, such that, during thermal expansion, the fender longitudinally shifts relative to the guide elements.
Since the inventive plastic fender is screwed down only in the corner region between the first and the second edge areas, it can shift during thermal expansion—whether caused by atmospheric exposure or during painting of the vehicle—along the edge area on both the hood side and the support column side, such that the plastic fender cannot bulge or otherwise deform. Since a rectangular mounting section of a guide element, which in turn is fixed to the vehicle body, engages in the elongated holes that are provided along the two edge areas of the plastic fender and is shorter than the corresponding longitudinal extent of the elongated hole, the plastic fender is guided exactly and unhindered in both longitudinal directions. Both the elongated holes and the guide elements can be provided very cost effectively. The guide elements are made of metal or plastic and have little weight.
The plastic fender, near the reference point formed by a screw, is held by a body-mounted screw with locating bushing in a through-hole with radial play, which is provided in the first edge area. This ensures that the plastic fender can slightly shift in relation to the reference point. The locating bushing, or instead thereof a correspondingly configured screw head, does not interfere with a hinge or similar fixture located in this area.
Because the plastic fender elongates more strongly in the area of its two free ends than in the area of the through-hole or the reference point, while the guide elements, on the other hand, are fixed to the vehicle body, the elongated holes have a steadily increasing longitudinal extent toward the area of the free ends of the fender. In other words, the length of the mounting section of a guide element remains constant, e.g., at 20 mm, but the length of an elongated hole near the through-hole measures, e.g., 30 mm, and the length of an elongated hole near the free end of the fender approximately 45 mm. Thus, the plastic fender can elongate unhindered, but for strength reasons, the elongated holes near the through-hole or the reference point do not have the same longitudinal extent as the elongated holes at the free ends of the fender.
To enable the guide elements to be detachably mounted to the vehicle body they are provided with a mounting section that is rectangular in top view. The width of the mounting section is smaller than the width of the elongated hole, such that the plastic fender can shift longitudinally unhindered, irrespective of thermal expansion or production and assembly tolerances. The mounting section can be mounted to the vehicle body in a simple manner using a screw that goes all the way through or—if made of plastic—using a one-piece screw shank.
To ensure that the plastic fender is always precisely guided as it shifts in longitudinal direction because of thermal expansion, a guide edge protrudes from each of the two long sides of the rectangular mounting section of the guide elements and covers the longitudinal edge of an elongated hole facing it while leaving an air gap. A bevel provided at each end face of the guide edges, which is approximately 1.5 to 2 mm wide and extends at an approximately 20° angle to the end face, further ensures that the plastic fender shifts perfectly in longitudinal direction. Finally, at the two end faces of the mounting section, in the corner regions thereof, an approximately 2 mm wide bevel is formed, which likewise extends at an approximately 20° angle to the end face of the mounting section.
In accordance with one feature of the invention, contact surfaces are provided at the bottom in the area of the two end faces of the mounting section to ensure that the mounting section presses slightly into the surface of the vehicle body during tightening so as to be secured against rotation.
An embodiment of the invention will now be described in greater detail, by way of example, with reference to the drawings.